Cast concrete construction

ABSTRACT

The present invention relates to a concrete construction having a number of cast-in bar-shaped displacement bodies of plastic, e.g., polystyrene, which are held in place by a number of anchorelements. A concrete construction of this type is known from the Dutch Patent Application 70 18413. The displacement body has a quadrangular cross-section and is clamped by means of a channel shaped clip, which exclusively engages the bottom-section of the bar and itself is clamped between parts of the casing. Since will small dimensions of the displacement bodies, the buoyancy forces, acting during casting and hardening of the concrete, play a relatively minor role, such a unilateral engagement can be admissable. However, for larger dimensions of the displacement bodies having large buoyancy forces such as a construction is not adequate and the danger arises that the displacement bodies will float. An object of the present invention aims at eliminating this disadvantage and to supply a concrete construction, in which the floating of the displacement bodies which may have large dimensions and correspondingly large buoyancy is prevented.

United States Patent [191 Bisschops et al.

[ CAST CONCRETE CONSTRUCTION 22 Filed: Aug. 14,1972

21 Appl. No; 280,700

[52] US. Cl ....IT.:..[..:.I..1Q 52/57152/669 H [51] Int. Cl. E04c 5/20, E04c 3/29 [58] Field of Search 52/669, 722, 577, 650, 52/667 [5 6] References Cited UNITED STATES PATENTS 1,354,998 10/1920 Paulson 52/669 2,179,554 11/1939 Hadley 3,488,909 l/l970 'Bahr 52/382 FOREIGN PATENTS OIiAFPLiATiBNs w 164,341 4/1949 Austria 52/381 18,178 8/1906 Great Britain 52/722 818,413 10/1951 Germany 52/669 [111 3,837,131 1 Sept. 24, 1974 Primary Examiner-John E. Murtagh Assistant Examiner-James L. Ridgill, Jr. Attorney, Agent, or Firm-Latias, Parry, Von Gehr, Goldsmith & Deschamps 5 7] ABSTRACT The present invention relates to a concrete construction having a number of cast-in bar-shaped displacement bodies of plastic, e.g., polystyrene, which are held in place by a number of anchor-elements.

A concrete construction of this type is known from the Dutch Patent Application 70 18413. The displacement body has a quadrangular cross-section and is clamped by means of a channel shaped clip, which exclusively engages the bottom-section of the bar and itself is clamped between parts of the casing. Since will small dimensions of the displacement bodies, the buoyancy forces, acting during casting and hardening of the concrete, play a relatively minor role, such a unilateral engagement can be admissable. However, for larger dimensions of the displacement bodies having large buoyancy forces such as a construction is not adequate and the danger arises that the displacement bodies will float.

An object of the present invention aims at eliminating this disadvantage and to supply a concrete construction, in which the floating of the displacement bodies which may have large dimensions and correspondingly large buoyancy is prevented.

2 Claims, 2 Drawing Figures CAST CONCRETE CONSTRUCTION The present invention consists in a concrete construction having a plurality of cast-in, bar-shaped displacement bodies of plastics material, said bodies being held in place by at least one anchor element transversely located with respect to the bodies, wherein the cross-section of the displacement bodies is a regular octagon, and wherein the or each anchor element is or are provided with quadrangular anchor cavities, the sides of which are congruent with four non-adjacent sides of the octagon.

By means of the simply constructed quadrangularshape according to the invention a good anchorage for the octagonal displacement-bodies is obtained, which moreover have the advantage that they are applicable for applications, in which the quadrangular crosssection shape of the displacement bodies is non permissable due to tension concentrations arising at the corners.

The anchor elements may comprise'framework girders, the diagonals of which border the anchor cavities.

This has the advantage that the girders can also serve as a support for spacing the top and bottom reinforcing bars for the concrete.

Thanks to this shape of the girder much less, however, generally somewhat heavier breaking threads can be used as attachment of the whole construction to the casing. Owing to the flat planes and the octagonal cross-section an area is always well adapted to be walked on, using scaffolding. The scaffolding parts can also be placed over the border bars ofthe girders which are sufficiently strong therefore.

The framework girders may further comprise two symmetrical parts of which the border bars support a number of adjacent equilateral trapeziumshaped constructions which are connected with their top-sides for the construction of the complete girder, while the sides of the trapeziums constitute the diagonals of the adjacent anchor cavities.

By means of this divided construction the framework girders can easily be manufactured in a separate workshop and thereafter be arranged at the building site with simple transport. The rigidity, obtained after the connection, makes it possible that on the building site large areas can be arranged. The fitting of the displacement bodies into the framework girder on an area can also be done in a factory.

According to a feature of the invention the girder bars and the trapezium sides are bent from strip steel to form a channel iron section.

The present invention also relates to a framework girder and a displacement body defined for the application in the concrete construction according to the present invention.

An embodiment of the present invention will now be elucidated further by reference to the enclosed drawmg.

FIG. 1 shows a front view of an assembly ofa number of displacement bodies in a framework girder in two pieces.

FIG. 2 shows a perspective view of the assembly according to FIG. 1 included in a partially broken away concrete-construction.

According to the drawing the concrete construction 1, which must have the form of a number of mutually connected l-shaped cross-sections, comprises a number of displacement bodies 2a, 2b, 2c and 2d. These displacement bodies are bar-shaped having a cross-section of a regular octagon and are made of solid polystyrene which is formed with a press pressure of 15kg. The displacement bodies 2 can be cut by means of a glowing filament, when shortening is desired, or when lengthening is desired they can be attached to one another by means of adhesive tape. This can, if necessary take place on the building site too.

By means of framework girders 3 and 3' acting as anchor elements the displacement bodies 2a up to and including 2d are held in place in the concrete construction. These framework girders 3 are made of two symmetrical parts viz., the top section 4 and the bottom section 5. These comprise the border bars 6 and 7 which each support a number of adjacent equilateral trapezium shaped constructions 8 and 9 which are secured with their top sides 10 respectively 11 for the construction of the complete girder, as, e.g., by means of a pivot link (not indicated). After the connection of the two girder sections 4 and 5 the sides 12 and 13 respectively l4 and 15 of the trapeziums form a couple of diagonals of the framework girder intersecting each other.

In connected position of the two girder sections the diagonals form quadrangles with sides 12, l5, l3 and 14 which are congruent with four non subsequent sides l6, 17, 18 and 19 of the displacement bodies 2 and surround the displacement bodies 2 so that a correct anchoring is guaranteed.

Both the border bars 6 and 7 of the framework girder and the sides 12, 10 and 14 respectively 13, l1 and 15 of the trapeziums are bent from strip steel to form channel iron sections. This gives a simple possibility of manufacturing in a plant and the girders can be made on a mould to lengths of maximum 4, 5 m.

In the application of the present invention the rela tion of the upward pressure with respect to the permissable pressure on the polystyrene and the width of the strip steel of the quadrangles in the framework girders is favourable for each size of the displacement body.

The quadrangular form of the anchoring cavity of the girder give a permanent good relation with respect to the bevel planes of the octagonal-shape of the displacement body. Instead of trapeziums, triangles can also be used which are interconnected at the tops or adjacent to the tops.

What we claim is:

l. A concrete construction having cast therein a plurality of bar-shaped displacement bodies of plastic material, said bodies being held in place by a plurality of anchor elements transversely located with respect to the bodies, wherein the cross-section of the displacement bodies is a regular octagon and wherein each anchor element is provided with quadrangular anchor cavities, the sides of which engage with and are congruent with four non-adjacent sides of the octagonal displacement bodies, said anchor elements being formed from strip steel as a framework girder having diagonal members extended between top and bottom border bars to form the anchor cavities.

2. A framework girder for use in the concrete construction according to claim 1, formed as two opposed symmetrical sections, comprising border bars supporting a number of adjacent equilateral trapeziums having minor sides abutting corresponding opposing minor sides of the opposite section, the trapeziums and border bars being formed from strip steel, the trapeziums constituting the diagonals of adjacent cavities which are adapted to anchor octagonal displacement bodies of plastic material in predetermined spaced relationships. 

1. A concrete construction having cast therein a plurality of bar-shaped displacement bodies of plastic material, said bodies being held in place by a plurality of anchor elements transversely located with respect to the bodies, wherein the cross-section of the displacement bodies is a regular octagon and wherein each anchor element is provided with quadrangular anchor cavities, the sides of which engage with and are congruent with four non-adjacent sides of the octagonal displacement bodies, said anchor elements being formed from strip steel as a framework girder having diagonal members extended between top and bottom border bars to form the anchor cavities.
 2. A framework girder for use in the concrete construction according to claim 1, formed as two opposed symmetrical sections, comprising border bars supporting a number of adjacent equilateral trapeziums having minor sides abutting corresponding opposing minor sides of the opposite section, the trapeziums and border bars being formed from strip steel, the trapeziums constituting the diagonals of adjacent cavities which are adapted to anchor octagonal displacement bodies of plastic material in predetermined spaced relationships. 